Metallic culvert.



K. J. THORSBY.

` METALLIC GULVERT. APPLIOATION FILED PBB.14,1912.

Patented June 4, 1912.-

I fm! unirn sra'rns PATENT ernten.

KARL JOHAN THORSBY, OF OAKLAND, CALIFORNIA, ASSIGNOB, TO CALIFORNIACORRU# GATED CULVERT COMPANY, 0F OAKLAND, CALIFORNIA, A CORPORATION OFCALI- FORNIA.

the part round or arch type, designed foruse beneath railroad tracks,roadways and especially paved streets.

The object of my invention is to provide a strong and durable culvert of-this character, capable of being put up with a minimum labor cost, andinexpensive in manne facture. r

A further object of my invention is toprovide a simple and effectivearch-culvert, wh1ch may be made up of a number of sections and ofVseparate sheets' ofmetal, preferably corrugated, said sheets beingcurved.

as hereinafter explained.

To these ends and with these objects in.

view, my .invention lconsists in the novel culvert which I shall nowfully describe by reference to the accompanying drawings, in which-Figure 1 is a side elevation of the metallic section of my culvert,showing the union of* two plates of said section. Flg. 2 is an end Viewof the metallic section of the culvert, showing its cross-sectionalshape. Fig. 3 is a sectional perspective view of the culvert as it willappear in ordinary street construction.

The metallic section of the culvert consists of a plate or a pluralityof plates 1, prt-ferably corrugated as I have here shown. llvhen a'plurality of plates are used, they are united by overlapping one or morecorrugations, as shown at 10, in Fig. 1. The arch of the plates 1 isformed, as shown in Fig. 2. on a curve of relatively long radiusthroughout its greater portion, as, for lexample.VV between .the points13 and 14. Bevond these points, namely to the points 15 and 1Grespectively, the plates are bent on a curve of comparatively shortradius. lfrom the points 15.and 16 to the extremi ties 11l and 12respectively, the ends of the plates are left straight.

In l 1 ig. 3 I show the complete culvert, 1nvolving the metallic section1 and its envi- Specification of Letters` Patent.

METALLIC CULVER'I.

Patented June 4, 1912.

Application led February 14, 1912. Serial No. 677,610.l

ronment as will occur in street construction. 2 is a fundamental supportor base, upon which the metallic section 1 rests, which base forms thebottom of the culvert, being formed with a smooth surface of any desiredshape, as, for example, a shape as here shown, curving or incliningdownward to the middle, as. at 9, in order to give a largerwater-Way-and `reduced friction. 4 is the curb, and 5, 6, 7 and 8 showthe different grades of the street section.

.It is to be especially noted that the base 2, which may be made of anysubstantial material, such, for example, as concrete, continues up thesides of the metallic section 1, as shown at 3, to at least the fulllength of the straight portions thereof between the points 11-15 and12-16 heretofore described. The usual practice heretofore has been toformthe full length of partcircle culverts as a one-half or a less part'of a full circle.

lVith such a shape, when there is a wide base and a' comparatively shortrise the pressure on the extremities is very great, and in many caseshas cracked the concrete at these points. I have overcome this by theshape of the culvert section ,here shown.

By the usel of'the sheets or plates 1 of the metallic section having thelong curve of relatively great radius followed by the short curves ofrelatively small radius, succeeded by the straight sides or ends to theextremities, a'nd these latter being reinforced vby the uprising base at3, there follows as a result that as the side thrust stresses of thesections are distributed on these straight portions, the strai on theconcrete or other material composing the base is considerably reduced. c

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is- 1. In a metallic culvert Iof the arch-type,the metallic section thereof bent throughout, the greater portion of itsarch on a curve of relatively long radius, said curve being followed ateach .end with short curves of relatively small radius, and said shortcurves being followed by straight portions continuing to the extremitiesof the section sides.

2. A metallic culvert of the arch-type, comprising a metallic sectionbent throughout the greater portion of its arch on a curve of relativelylong radius, said curve being `followed at each end with short curves ofrelatively small radius, and said short .ing the bottom of the culvert.

3. A metallic culvert of the arch-type.` comprising a metallicsection'bent throughout the greater portion of its arch on a curve ofrelatively long radius, said curve being followed at each end with shortcurves of relatively small radius, vand said short curves being followedby straight portions continuing to the extremities of the section sides,and a base upon which the extremities of the metallic section rest, saidbase forming the bottom of the culvert, and continuing up the outside ofthe straight portions of the sides of said metallic section.

4'. A metallic culvert vof thel arch-type,

comprising a metallic section bent throughout the greater portion of itsarch on a curve of relatively long radius, said'curve being followed ateach end with short curves of relatively small radius, and said shortcurves bottom being inclined downward 'from each side, and said basecontinuing up the outside of the straight portions of the sides of thesaid metallic section.

. In testimony whereof I have signed my name to this specification inthe presence of two subscribing witnesses.

KARL JOHAN THORSBY. Witnesses:

' S. A. FORD,

C. R. HODGKIN.

